HEAT RESISTANT Ni-Al-Be ALLOYS

ABSTRACT

A group of three kinds of improved heat resistant alloys containing, Ni, Al and Be as main constituents, the first kind further comprising 0.01 - 4% of at least one of the additional elements Mo, Cr and Co, the second kind further comprising 0.01 to 1% of at least one of the additional elements Ti, Zr, V, Nb, W, Mn and Cu, and the third kind further comprising 0.01 to 4% of at least one of the additional elements Mo, Cr and Co and 0.01 to 1% of at least one of the additional elements Ti, Zr, V, Nb, W, Mn and Cu. These improved heat resistant alloys have excellent antioxidizing and high tensile properties at temperatures between 1,000* and 1,200* C and are highly adapted for use in manufacturing machine parts subjected to high temperatures and severe loads.

- Komatsu et al.

1451 Apr. 30, 1974 [54] HEAT RESISTANT Ni-AI-Be ALLOYS [75] Inventors: Noboru Komatsu; Takatoshi Suzuki;

Takuo Ito, all of Nagoya, Japan [73] Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho, Nagoya-shi, Aichi-ken, Japan 22 Filed: Dec. 27, 1971 21 Appl. No.: 211,993

[30] Foreign Application Priority Data Dec. 27, 1970 Japan 45-126092 [56] References Cited UNITED STATES PATENTS 3,704,182 ll/l972 Griffiths et al 75/171 Primary Examiner-Richard 0. Dean Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A group of three kinds of improved heat resistant alloys containing, Ni, Al and Be as main constituents, the first kind further comprising 0.01 4% of at least one of the additional elements Mo, Cr and Co, the second kind further comprising 0.01 to 1% of at least one of the additional elements Ti, Zr, V, Nb, W, Mn and Cu, and the third kind further comprising 0.01 to 4% of at least one of the additional elements M0, Cr and Co and 0.01 to 1% of at least one of the additional elements Ti, Zr, V, Nb, W, Mn and Cu.

These improved heat resistant alloys have excellent antioxidizing and high tensile properties at temperatures between 1,000 and 1,200 C and are highly adapted for use in manufacturing machine parts subjected to high temperatures and severe loads.

6 Claims, 2 Drawing Figures HEAT RESISTANT NI-AL-BE ALLOYS BACKGROUND ON THE INVENTION 1. Field of the Invention The present invention relates to the composition of heat resistant alloys having excellent oxidation resistance (antioxidizability) and tensile strength properties at high temperatures, particularly to those containing Ni, Al and Be as main constituents.

2. Description of the Prior Art With modern advancement and development of technology and industry, the demand for high temperature heat resistant materials, especially those durable to temperatures substantially higher than 1,000C is amazingly increasing. These materials are now required for various uses in the manufacture of various apparatuses and their parts, which are subjected to high temperatures and severe loads, such as rocket shells, atomic thermoengines, combustion chambers and jet pipes of jet propulsion engines, parts of gas turbines, high temperature and pressure devices for chemical plants, high temperature valves and the like.

Although numerous and profound studies have been made in the field of the heat resistant materials and many kinds of heat resistant alloys have been used, many shortcomings and problems still remain and need to be improved. As an example, it is well known that the practical temperature ranges of heat resistant steels and heat resistant alloys, containing Ni or Co as the main constituents, are below 800 and 1,000C, respectively. They can not be used, therefore, at temperatures higher than the respective temperatures for an extended period because of their low tensile strength and poor antioxidizability. Super heat resistant alloys, such as Mo, Nb, Ta alloys, and ceramics can be used for a long service period at higher temperatures and l,0OC. However, these super heat resistant alloys exhibit very poor antioxidizing properties at high temperatures so that the conditions for using them are highly limited or one must necessarily perform surface treatinents for preventing them from oxidization. The ceramics have a tendency to break under rapid and substantial temperature fluctuations and also exhibit lack of ductility at every temperature and of resistibility to thermal shocks. It may therefore be definitely concluded that new heat resistant alloys should be developed or the conventional heat resistant materials must be greatly improved.

As a material having excellent antioxidizability and tensile strength at higher temperatures, we developed certain Ni-Al-Be alloys previously and filed thereon an application for patent (Ser. No. 59l69, now U.S. Pat. No. 3,715,206). The present invention concerns itself with further improvements of these alloys; it especially improves their tensile strength at higher temperatures without lowering their high performance of antioxidizability.

SUMMARY OF THE INVENTION The improvement has been attained in the present invention by adding small amounts of specifically selected elements to the prior proposed Ni-Al-Be alloys.

It is a primary object of the present invention to provide heat resistant alloys having excellent tensile strength at temperatures higher than l,000C.

It is another object of the present invention to provide heat resistant alloys having excellent tensile strength and antioxidizing properties.

It is a further object of the present invention to provide heat resistant alloys containing Ni, Al and Be as their main constituents and having excellent tensile strength and antioxidizing properties.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will best be understood from the following detailed description of specific embodiments thereof when read in connection with the drawing, and in which:

FIG. 1 is a Ni-Al-Be triangular coordinate diagram represented by weight percentage, which show the constituents of Ni, Al and Be of the heat resistant alloys according to the present invention.

FIG. 2 is a Ni-Al-Be triangular coordinate showing said constituents by atomic percentage.

DETAILED DESCRIPTION OF THE INVENTION From the results of a large number of experiments, we have found three kinds of highly improved heat resistant alloys which possess remarkably high tensile strengths at temperatures in the range of l,000 to 1,200C. These heat resistant alloys contain Ni, Al and Be, as main constituents, and a small amount of at least one of specifically selected elements. The main constituents Ni, Al and Be are present in specific ratios thereamong that; Le, they are present in amounts residing in the area ABCD in the triangular coordinate diagram shown in FIG. 1. The ratios or percentages at the points A, B, C and D are shown in Table 1 below both in atomic percentage and weight percentage. In other words, the three kinds of heat resistant alloys are formed from the alloy defined by the said area AB- C-D and a small amount of at least one of the specific elements set forth below. Hereinafter, the main constituents: of Ni, Al and Be which have the relative ratio of a Ni-Al-Be alloy defined by the area A-B-C-D in FIG. 1, will be called the basic components. The relative ratio or percentage of all included elements will be given by weight percentage (wt. except when otherwise specified. Further, the triangular coordinate dia gram in FIG. I is shown in the form of an equilateral one. The base line of the triangular coordinate represents percentages of Al; the right and left sides represent those of Be and Ni, respectively. Therefore, the percentages of Al are shown by the lines parallel to the left side, and those of Ni and Be are shown by the lines parallel to the right side and the base line, respectively.

Forexample, point Y in FIG. 1 represents the constituents ratios of Ni%, Al-20% and Be-I0%.

One of the three kinds of heat resistant alloys is formed of 0.01 to 4% of at least one of the elements Mo (molybdenum), Cr (chromium) and Co (cobalt), with the remainder being 96 to 99.99% of the basic components (hereinafter referred to as the first range heat resistant alloys).

The second kind of heat resistant alloys are made of 0.01 to 1% of at least one element selected from the group consisting of Ti (titanium), Zr (zirconium), V (vanadium), Nb (niobium), Ta (tantalum), W (tungsten), Mn (manganese) and Cu (copper), the remainder being 99 to 99.99% of the basic components (referred to as the second range heat resistant alloys).

In said application for patent (Ser. No. 59169, new U.S. Pat. No. 3,715,206), the Ni-Al-Be percentage is shown in atomic percent (at. as shown in FIG. 2, however in the present invention, the Ni-Al-Be percentage is shown in weight percent (wt. as shown in FIG. 1, to clarify the rate of the elements of the alloy in the present invention.

The third kind of heat resistant alloys contain from 0.01 to 4% of at least one element selected from the group consisting of Mo, Cr and Co, from 0.01 to 1% of at least one element from the group consisting of Ti, Zr, V, Nb, Ta, W, Mn and Cu, and the remainder being 95 to 99.98% of the base components (referred to as the third range heat resistant alloy).

With regard to the basic components of Ni, Al and Be, we developed ternary Ni-Al-Be alloys residing in the area A-EF'-B'C'-D' shown in FIG. 2 and filed thereon an application for patent (Ser. No. 59169, now U.S. Pat. No. 3,715,206). The area A'-E'-B-C'-D' shown in FIG. 2 (the area A B-C-D in FlG.l), specifying the basic components, has been taken from the area A-E'-F'-B'-C'-D. In other words, the area EF-B', specifying the alloys containing a high content of Ni, has been excluded from the said area A'-E'B'-C'-D.

Also, the ratio of each element shown in FIG. 1 is the additional eight elements, Ti, Zr, V, Nb, Ta, W, Mn and Cu, has been specified to be 0.01%. The reason is such that use of an amount less than 0.01% of the additional elements can contribute little improvement to the tensile strength of the alloys at high temperatures. The highest limit, 1%, has been specified for such reason that no further improvement can be expected of the tensile strength by adding these elements in amounts higher than .1%. Addition of one or more elements selected from the said eight elements including Ti, V and Cu can contribute to the desired effect so long as they are used in the range from 0.01 to 1%.

The third range heat resistant alloys according to the invention includes the same basic components as those of the first and second range alloys. And, the amounts of the lementsWo Beadde d to the basic components are specified to be from 0.01 to 4% of one or more elements selected from the group consisting of Mo, Cr, and Co and from 0.01 to 1% of one or more elements selected from the group consisting of the eight elements included in the second range heat resistant alloys because of the similar reasons for the first and second range heat resistant alloys. Therefore, the third range heat resistant alloys are composed of 0.02 to 5% of the additional elements and 95 to 99.98% of the basic comratio prevailing among the basic components, and thus ponents.

Specified At., percent Wt., percent Specified points points FIG. 2 Ni Al Be Ni Al Be in FIG I A 50.1 0.1 49.8 86.7 0.1 13.2 A B 74.0 24.0 2.0 86.7 12.9 0.4 B C 48.0 50.0 2.0 67.3 32.2 0.4 C D 48.0 0.1 51.9 85.7 0.1 14.2 D E 61.0 11.0 28.0 86.7 7.2 6.1 F' 87.0 11.0 2.0 94.2 5.5 0.3

is not the ratio in the alloy containing the added elements. For example, an alloy consisting of 98% of the basic components which consist of 60% Ni, Aland 10% Be, and the remaining 2% of Mo as an added element, contains 58.8 of Ni 60 X 0.98), 29.4% of A1 30 X 0.98), 9.8% of Be (=10 X 0.98%) and 2% of M0.

The amount of the added elements in the first range heat resistant alloys is specified to be from 0.01 to 4%. The reason for adopting the minimum limit, 0.01 is such that an addition of less than 0.01 of the elements will contribute little to the improvement of the tensile strength of the alloy at high temperatures. The maximum limit is specified to be 4% for such reason that no further improvement can be expected of the tensile strength by adding these elements in amounts higher than 4%. An addition of one or more elements selected from the group consisting of Mo, Cr and Co, can contribute to the desired improvement so long as the amount of the element or elements is in the range of 0.01 to 4%.

The second range heat resistant alloys according to the present invention contain the same basic components as those of the first range heat resistant alloys specifically referred to above. The lower limit of the All the alloys of the examples were prepared by melting the constituents together by the high frequency heating method and then casting the resulting molten alloy into a graphite mold. The casted products were subjected to an antioxidizing test and a tensile strength test, respectively. The antioxidizing test was performed by measuring the weight increase of a sample (having a 10 mm diameter and a 5 mm height) after heating the sample in the open air atmosphere for 5 hours at 1,200C. The antioxidizability is demonstrated as the ratio of the weight increase (in mg) divided by the whole surface area of the sample (cm). Naturally, a smaller ratio means better antioxidizability.

For performing the tensile strength test, the cast alloy products were firstly heated for 10 hours at 1,200C and then, cooled down in a furnace for homogenizing its structure. Then, it was machined to make a test piece, having a 35 mm length and a 17 mm central parallel part with a 4 mm diameter. The test'pieces were tested at a'testing temperature of 1,000 to 1,200C as shown in each example and a tensile velocity of 2.5 mm/min after keeping the test piece at the same testing temperature for about 15 minutes. The test results are shown as tensile strength (kg/mm). Also the elongation of the test pieces are shown for reference. The

S 136th tests were made on the alloys consisting exclusively of the basic components.

6. test. The test results and the percentages of the constituents of each alloy are shown in Table3.

EXAMPLE 1 Twelve kinds of alloys were tested. One of them (m was an alloy consisting essentially of the basic components (approximately Ni78.3%, Al-l 5.5% and Be-6.2%). The others (lto 11) were composed of 99% of the same basic components as m and 1% of one of the eleven elements: Mo, Cr, Co, Ti,'Zr, Nb, V, Ta, W, Mn and Cu. The tensile strength test at 1,100C and antioxidizability test were made on each of the test pieces. The test results and the percentages of the constituents for each test piece are shown in Table 2.

As shown in Table 3, Samples Nos. 12 to 15, containing Mo, and Samples Nos. 16 to 18, containing Ti, represented excellent antioxidizabilities ranging from 0.14 to 0.36 mg/cm And, it was observed that there were little changes in the antioxidizabilities by variation of the amount of the added additional element M or Ti. With regard to their tensile strengths, an addition of Mo appreciablyimproved the tensile strengths as is apparent by comparing the increase thereof from the tensile strength of Sample m 16.6 kg/mm. The addition of 2% MO presented the maximum value 23.5 kglmm and addition of 1% Mo and 4% Mo, respectively, re-

TABLE 2 Addi- Antitional Constituents (wt. oxidiz- Tensile Elon- Sample element ability, strength. gation. No. Ni AI Be X mg/cm kg/mm percent With regard to antioxidiiabilityjthe worst antioxidiz ability among the samples 1 to 11 which represent the alloys of the invention, is only 0.7 mg/cm presented by Sample No. which contains an additional element Zr. The other Samples Nos. 1 to'4 and 6 to 1 1 represented almost the same or slightly lower antioxidizability when compared with the antioxidizability of m which consists exclusively of the basic components developed previously by us. Since a Nimonic 90"-alloy, well ,known by its excellent antioxidizability, represented 3.0 mg/cm by the same test, the Samples Nos. 1 to 1 1 were proved to possess a remarkably high antioxidizability when compared with that of Nimonic 90.

With regard to tensile strength, when compared with the tensile strength 16.6 lag/mm of Sample m the alloys of the invention, represented by Samples 1 to 11, showed -50% higher tensile strengths. Therefore, an addition of the eleven additional elements has proved to be highly effective for improving the tensile strength of the alloy consisting essentially of the basic components.

EXAMPLE 2 Alloys of the same basic components as used in, the

foregoing Example 1, and containing from 0.1 to 4% of M0, or from 0.1 to 2% of Ti were subjected to the tensile strength test at l,l00C and the antioxidizability sulted in slightly lower values than the above-specified maximum value.

By addition of Ti in amounts of at least up to Ti 1%, the tensile strength was increased. However, the tensile strength as obtained by addition of 2% Ti was lower than the case of Sample m including no amount of the additional element Ti.

According to further tests on the alloys including other additional element or elements Cr and Co presented the same tendencies as those of Mo, and Zr, V, Nb, Ta, W, Mn and Cu presented the same tendencies as those of Ti.

EXAMPLE 3 TABLE 4 Additional ele- Antiment added Constituents (wt. oxidiz- Tensile Elon Sample ability, strength, gation, No. X X Ni Al Be X X mglcm kglmm percent 78.3 15.5 6.2 0.15 16.6 27 Cr 77.2 15.0 5.8 1.0 1.0 .21 22.9 Co 77.] 15.1 5.8 1.0 1.0 .21 23.7 9 Co 77.4 15.0 5.6 1.0 1.0 .18 20.2 38 Nb 76.5 15.5 6.0 1.0 1.0 .30 17.8 0 Cu 77.1 15.1 5.8 1.0 1.0 .17 23.4 0 Nb 79.1 12.4 6.5 1.0 1.0 .28 25.8 1

As shown in Table 4, the alloys added with mixed ad- EXAMPLE-5 ditional elements exhibited excellent antioxidizabilities as the alloys added with one additional element only. And, an addition of additional elements proved to contribute effectively to the improvement of the tensile strength. Especially, the addition of the mixed elements Mo and Nb contributed to a 50% increase in tensile strength.

EXAMPLE 4 results of the alloys are shown in Table 5.

Alloys containing 99% of the basic components in different amounts of constituents and 1% of Cu or M0 were subjected to the tensile strength test at 1,100C and the antioxidizability test. The percentages of the constituents and the test results of the alloys are shown in Table 6. Each Sample of the basic components is shown with the same number of the Sample as the corresponding point of the constituents in FIGS. 1 and 2. With regard to the Samples m, to m which are composed exclusively of the basic components, Sample m contains approximately the same volumes of the betaphase and delta-phase. Samples m and m contain respectively the beta-phase and gamma-phase as their main phase. Samples m and m have a delta-phase structure as the main phase. The beta-phase means such a phase as being composed of an intermetallic compound NiAl having solid solute or solutes of Be, Be

As a reference, ternary Ni-Al-Be alloys consisting exclusively of the basic components were tested at each testing temperature and the results and percentages of the constituents are also shown in Table 5.

As shown in Table 5, the alloys containing one or more of these additional elements showed an appreciable increase in tensile strength at each testing temperature, when compared with the corresponding tensile strengths of the alloys composed exclusively of the basic components. Especially, at the high testing temperature of 1,200C, although the alloy consisting exclusively of the basic components exhibited a tensile strength of 5.7 kg/mm, the alloy containing Nb and Mo exhibited about a l30%-incrcase, and the alloy added with Cu represented about a l0()%-increase. The influence of these added elements was remarkable, especially at high temperatures.

and Al, or Be and Ni dissolved therein. The beta-phase has such a structure of the alloys corresponding to the 7 point C in FIG. 1 or close proximity thereof. The gamma-phase is such a phase as composed of an intermetallic compound Ni Al, having solid solute or solutes of Be, Be and Al or Be and Ni dissolved therein. The gamma-phase has such a structure of the alloys corresponding to the point B in FIG. 1 or close proximity thereof. The delta-phase is such a phase as composed of an intermetallic compound NiBe having solid solute or solutes of Al, Al and Be, or Al and Ni dissolved therein. The gamma-phase has such a structure of the alloys corresponding to the points A and D in FIG. 1 or close proximity thereof.

As shown in Table 6, in any case of the basic components, the addition of Mo or Cu to the basic components increased appreciably the tensile strength with- TABLE 6 Anti- Added Constituents (wt. oxidiz- Tensile Elon- Sample element ability, strength, gation, No. Ni Al Be X mg/cm kg/mm percent out lowering its high antioxidizability. Therefore, it can be seen that heat resistant alloys having high antioxidizability and tensile strength properties can be produced by the addition of M0 or Cu to the beta, gamma or delta phases. According to our further experiments, we have observed that each of the alloys composed of 99% of the basic components, having the same relative amounts of the constituents as those of sample m,,, and of'1% of one of the elements Mo, Ti and Ta, exhibited a tensile strength ranging between about 12 and 15 kg/mm and approximately the same antioxidizability as that of Sample m composed exclusively of the basic components. Similarly, each of the alloys composed of 99% of the basic components, having the same relative amount of constituents as those of Sample m and of 1% of one of the elements Cr, Nb and W, exhibited a tensile strength between about 5 and l l kg/mm Each of the alloys composed of 99% of the'basic components, having the same relative amounts of the constituents as those of Sample 10, and the remainder 1% of one of the elements Co, V and Mn, exhibited a tensile strength ranging between about 13 and 16 kglmm Each of the alloys composed of 99% of the basic components, having the same relative amounts of the constituents as those of Sample m and the remainder 1% of one of the element Cr, Zr and Cu, exhibited a tensile strength ranging between about 22 and 25 kg/mm. The antioxidizability of each of the alloys was approximately the same as that of each of the corresponding basic components. And, it has been proven that the ad dition of the elements to any of the basic components could contribute to the increase of tensile strength. Further, we studied the metallurgical structure of alloys having the same basic components as Sample m,, with the remainder composed of one of the added elements Co, Ti and Cu, relying upon the X-ray and electron beam scattering methods. According to the experimental results, the C0 is dissolved mainly inthe delta-phase and the Ti and Cu are dissolved mainly in the betaphase. These solid-solutions are considered to contribute to the reinforcement of the basic components.

As described above, the three kinds of heat resistant alloys according to the present invention are excellent in antioxidizability and their high temperature strength Ni-Al-Be alloys in their tensile strength at high temperatures. Therefore, the alloys of the invention are supe rior to the Ni-Al-Be alloys and highly superior to the conventional alloys in the overall antioxidizability and high temperature tensile strength properties.

Further, with regard to the constituents of the alloys, the basic components or main constituents of the al loys, Ni, Al and Be, do not necessarily have to be pure. Commercially available metallic Ni, Al and Be; commercial Ni-Be alloys; Al-Be alloys and the like can be used as the material for the preparation ofthe alloys of the invention. Even if a small amount of impurities such as Fe and Si is introduced into the alloys, the impurities will not adversely affect the excellent properties of the alloys so long as the amount of the impurities is reasonably small. Similarly, the impurities may be introduced together with the eleven additive elements since they do not adversely affect the properties because the amount of the additional elements added to the alloys are so small that the impurities contained therein represent very little of the final alloys. lf carbon enters into the alloys from a melting furnace or the like during making and melting the alloys, there may be substantially no adverse effects as long as the amount of the carbon is small.

The alloys according to this invention exhibit a slightly yellowish metallic color, appearing generally as a slight modification to the normal metallic color of fresh steel or iron.

The density, g/cm, of these alloys are shown only representatively as followsz Density 6.0 5.93-6.08

Sample l Hardness, H, 517 517 520 521 522 520 555 500 Sample As for the melting range, the

following is representatively shown.

Melting Range, "C

-initiation of termination of Sample solidification solidification m, 1,418 1,383 1 3 1,400 1,382

Thermal Expansion Coeff.

Sample The thermal conductivity, kcal/mhrC, is representatively as follows:

Sample Thermal Conductivity m 28.9

MANUFACTURING EXAMPLE Al 1.55 kg, 80 0.67 kg and Ni 7.778 kg were used. Ni and Al were firstly charged in a crucible made of MgO and melted by use of a conventional high frequency induction heating means. Be-pellets separately preheated were added to the molten charge and thoroughly agitated under heating, until all the constituents represented a unified phase. Then, additional element or elements was/were added thereto. Finally, the molten alloy was molded in the desired shapes. All the constituents were of the industrial grade. The above melting procedures were performed entirely in the open atmosphere. The yield of the constituent Be was about 90%, while those of Ni and Al amounted to almost 100%, respectively.

As were referred to above, the heat resistant alloys according to this invention can be prepared under the open atmosphere. In this connection, it should be stressed that a floating layer of beryllium oxide is formed during the melting process on the molten charge so that invasion of N and therein is substantially prevented and thus the alloys contain the least possible adsorbed or occuluded amount of these disadvantageous gases.

As is seen from the foregoing disclosure, the alloys according to this invention have a smaller density in general and thus can be advantageously utilized for the manufacture of rotor vanes of a gas turbine. Thanks to the higher specific strength, those vanes prepared from the alloys according to this invention can bear more advantageously the high centrifugal force imposed on these vanes in their operation.

The embodiments of the invention in which an exclusive property or privilege is claimed are as follows:

1. A heat resistant alloy comprising as its main constituents Ni, Al and Be, wherein the amounts thereof are defined by and included in a polygonal area on a triangular coordinate diagram of Ni, Aland Be, said polygon having the following four apexes in said triangular coordinate diagram, in weight percent:

Ni Al Be 86.7 0.1 13.2 86.7 12.9 0.4 67.3 32.3 0.4 85.7 0.1 14.2

said alloy further comprising from 0.01 to 4% by weight, based on the total weight of the alloy, of at least one member selected from the group consisting of Mo, Cr and Co.

2. A heat resistant alloy comprising as its main constituents Ni, Al and Be, wherein the amounts thereof are defined by and included in a polygonal area on a tri- 12 angular coordinate diagram of Ni, Al and Be, said polygon having the following four apexes in said triangular coordinate diagram, in weight percent;

Ni Al Be 86.7 0.1 13.2 86.7 12.9 0.4 67.3 32.3 0.4 85.7 0.1 14.2

said alloy further comprising from 0.01 to 1% by weight, based on the total weight of the alloy, of at least one member selected from the group consisting of Ti, Zr, V, Nb, Ta, W and Mn.

3. A heat resistant alloy comprising as its main constituents Ni, Al and Be, wherein the amounts thereof are defined by and included in a polygonal area on a triangular coordinate diagram of Ni, Al, and Be, said polygonal having the following four apexes in said triangular coordinate diagram in weight percent:

Ni Al Be 86.7 0.1 13.2 86.7 12.9 0.4 67.3 32.3 0.4 85.7 0.1 14.2

said alloy further comprising from 0.01 to 4% by weight, based on the total weight of the alloy, of at least one member selected from the group consisting of Mo, Cr and Co and from 0.01 to 1% by weight, based on the total weight of the alloy, of at least one member selected from the group consisting of Ti, Zr, V, Nb, Ta, W and Mn.

4. A heat-resistant alloy having good anti-oxidizing properties and excellent tensile strength at temperatures higher than 1,000C., said alloy consisting of:

A. from 96 to 99.99% by weight, based on the weight of the alloy, of Ni, Al and Be, the amount of each of said Ni, Al and Be being defined by and included within the figure ABCD in FIG. 1; and

B. from 0.01 to 4% by weight, based on the weight of the alloy, of at least one member selected from the group consisting of Mo, Cr and Co.

5. A heat-resistant alloy having good anti-oxidizing properties and excellent tensile strength at temperatures higher than 1,000C., said alloy consisting of:

A. 99 to 99.99% by weight, based on the weight of the alloy, of Ni, Al and Be, the amount of each of said Ni, Al and Be being defined by and included within the figure ABCD in FIG. 1; and

B. from 0.01 to 1% by weight, based on the weight of the alloy, of at least one member selected from the group consisting of Ti, Zr, V, Nb, Ti, W and Mn.

6. A heat-resistant alloy having good anti-oxidizing properties and excellent tensile strength at temperatures higher than 1,000C., said alloy consisting of:

A. to 99.98% by weight, based on the weight of the alloy, of Ni, Al and Be, the amount of each of said Ni, Al and Be being defined by and included within the figure ABCD in FIG. 1; and

B. from 0.01 to 4% by weight, based on the weight of the alloy, of at least one member selected from the group consisting of Mo, Cr and Co and from 0.01 to 1% by weight, based on the weight of the alloy, of at least one member selected from the group consisting of Ti, Zr, V, Nb, Ta, W and Mn. 

2. A heat resistant alloy comprising as its main constituents Ni, Al and Be, wherein the amounts thereof are defined by and included in a polygonal area on a triangular coordinate diagram of Ni, Al and Be, said polygon having the following four apexes in said triangular coordinate diagram, in weight percent; Ni Al Be 86.7 0.1 13.2 86.7 12.9 0.4 67.3 32.3 0.4 85.7 0.1 14.2 said alloy further comprising from 0.01 to 1% by weight, based on the total weight of the alloy, of at least one member selected from the group consisting of Ti, Zr, V, Nb, Ta, W and Mn.
 3. A heat resistant alloy comprising as its main constituents Ni, Al and Be, wherein the amounts thereof are defined by and included in a polygonal area on a triangular coordinate diagram of Ni, Al, and Be, said polygonal having the following four apexes in said triangular coordinate diagram in weight percent: Ni Al Be 86.7 0.1 13.2 86.7 12.9 0.4 67.3 32.3 0.4 85.7 0.1 14.2 said alloy further comprising from 0.01 to 4% by weight, based on tHe total weight of the alloy, of at least one member selected from the group consisting of Mo, Cr and Co and from 0.01 to 1% by weight, based on the total weight of the alloy, of at least one member selected from the group consisting of Ti, Zr, V, Nb, Ta, W and Mn.
 4. A heat-resistant alloy having good anti-oxidizing properties and excellent tensile strength at temperatures higher than 1, 000*C., said alloy consisting of: A. from 96 to 99.99% by weight, based on the weight of the alloy, of Ni, Al and Be, the amount of each of said Ni, Al and Be being defined by and included within the figure ABCD in FIG. 1; and B. from 0.01 to 4% by weight, based on the weight of the alloy, of at least one member selected from the group consisting of Mo, Cr and Co.
 5. A heat-resistant alloy having good anti-oxidizing properties and excellent tensile strength at temperatures higher than 1, 000*C., said alloy consisting of: A. 99 to 99.99% by weight, based on the weight of the alloy, of Ni, Al and Be, the amount of each of said Ni, Al and Be being defined by and included within the figure ABCD in FIG. 1; and B. from 0.01 to 1% by weight, based on the weight of the alloy, of at least one member selected from the group consisting of Ti, Zr, V, Nb, Ti, W and Mn.
 6. A heat-resistant alloy having good anti-oxidizing properties and excellent tensile strength at temperatures higher than 1, 000*C., said alloy consisting of: A. 95 to 99.98% by weight, based on the weight of the alloy, of Ni, Al and Be, the amount of each of said Ni, Al and Be being defined by and included within the figure ABCD in FIG. 1; and B. from 0.01 to 4% by weight, based on the weight of the alloy, of at least one member selected from the group consisting of Mo, Cr and Co and from 0.01 to 1% by weight, based on the weight of the alloy, of at least one member selected from the group consisting of Ti, Zr, V, Nb, Ta, W and Mn. 